Thanks for the link! I bought one, drilled the string hole a bit bigger, and added brass inlays, then re stained it. I wouldn’t have stained it if I hadn’t dented it in the process, but live and learn.

That looks fantastic! Is the brass inlay piece something that is purchased made (I.e. could it be done by someone with few tools and little knowledge)? My umbrella has arrived at last, I’ve taken out the string, and would like to close that hole if I could work it out.

I hand sawed a piece of brass rod that was similar size to the hole, then used a sanding disc to sand flat, but it could be sanded flat with just a piece of sandpaper sitting on a table.
Depending on your brass rod, you may need to drill out the hole just a tad. Other than that, no big tools needed.

Suggestion, instead of doing a single brass rod, make 2 small ones. That way you don't have to have the exact size rod and sand flush. You add glue in the hole, then push it in until is sits flush, then do the same on the other side.